Nuclear Theory·nucl-th

Thursday·October 26, 2023

10 papers—6 primary·4 cross-listed

01
[Submitted on 24 Oct 2023]
The renormalization of the shell-model GT operator starting from effective field theory for nuclear systems
L. Coraggio🇮🇹 · N. Itaco🇮🇹 · G. De Gregorio🇮🇹 · A. Gargano🇮🇹 · Z. H. Cheng🇨🇳 · Y. Z. Ma🇨🇳 · F. R. Xu🇨🇳 · M. Viviani🇮🇹
For the first time, we approach in this work the problem of the renormalization of the Gamow-Teller decay operator for nuclear shell-model calculations by way of many-body perturbation theory, starting from a nuclear Hamiltonian and electroweak currents derived consistently by way of the chiral perturbation theory. These are the inputs we need to construct microscopically the effective shell-model Hamiltonians and decay operators. The goal is to assess the role of both electroweak currents and many-body correlations as the origins of the well-known problem of the quenching of the axial coupling constant gA. To this end, the calculation of observables related to the Gamow-Teller transitions has been performed for several nuclear systems outside the 40Ca and 56Ni closed cores and compared with the available data.
Comments:
15 pages, 13 figures, 3 tables, to be published in Physical Review C
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2310.16133 [pdf]
PRC(2024)·25 citations
02
[Submitted on 24 Oct 2023]
Space-time structure of particle emission and femtoscopy scales in ultrarelativistic heavy-ion collisions
Yu. M. Sinyukov · V. M. Shapoval · M. D. Adzhymambetov
The analysis of the spatiotemporal picture of particle radiation in relativistic heavy-ion collisions in terms of correlation femtoscopy scales, emission and source functions allows one to probe the character of evolution of the system created in the collision. Realistic models, like the integrated hydrokinetic model (iHKM), used in the present work, are able to simulate the entire evolution process of strongly interacting matter produced in high-energy nuclear collision. The mentioned model describes all the stages of the system's evolution, including formation of the very initial state and its consequent gradual thermalization, hydrodynamic expansion and afterburner hadronic cascade, that can help researchers to figure out the specific details of the process and better understand the formation mechanisms of certain observables. In the current paper we investigate the behavior of the pion and kaon interferometry radii and their connection with emission functions in ultrarelativistic heavy-ion collisions at the Large Hadron Collider within iHKM. We are focusing on the study of the emission time scales at different energies for both particle species (pions and kaons) aiming to get deeper insight into relation of these scales and the peculiarities of the mentioned system's collective expansion and decay with the experimentally observed femtoscopy radii. One of our main interests is the problem of the total system's lifetime estimation based on the femtoscopy analysis.
Comments:
28 pages, 9 figures. "Author edition" of the recently published article
Subjects:
Nuclear Theory (nucl-th); High Energy Physics — Experiment (hep-ex); High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex)
arXiv:
2310.16233 [pdf]
Universe(2023)·5 citations
03
[Submitted on 25 Oct 2023]
Pauli resonance states in light nuclei: how they appear and how they can be eliminated
N. Kalzhigitov · V. S. Vasilevsky
Systematic analysis of parameters and properties of the Pauli resonance states are performed for light nuclei $^{6}$ Li, $^{7}$ Li, $^{8}$ Be, $^{9}$ Be and $^{10}$ B, which are treated as two-cluster systems. The Pauli resonance states are redundant solutions of the resonating group method appearing when one try use more advanced description of the internal structure of interacting clusters. Our calculations are performed in a standard and advanced versions of the resonating group method. The standard version employs wave functions of many-particle shell model to describe internal motion of nucleons within each cluster. The advanced version is based on three-cluster resonating group method. As in the standard version, the internal wave functions of three clusters are approximated by wave functions of many-particle shell model model. However, in advanced version one of pair of clusters forms a bound state, and third cluster is considered to interact with such state. It is found that the Pauli resonance states in nuclei under consideration have energy between 11 and 46 MeV, and their widths vary from 8 keV to 6.7 MeV. Analysis of wave functions of Pauli resonance states and matrix elements of norm kernel allowed us to formulate an effective method for eliminating Pauli resonance states. It is demonstrated that this method effectively eliminate all determined the Pauli resonance states.
Comments:
54 pages, 28 figures, typos are corrected and few paragraph are added with more detailed explanations, submitted to Phys. Rev. C
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.16373 [pdf]
PRC(2024)·0 citations
04
[Submitted on 25 Oct 2023]
Muonic hyperfine structure and the Bohr-Weisskopf effect
J.R. Persson🇳🇴
An update is given on the experimental values of the magnetic hyperfine structure and the Bohr-Weisskopf effect in muonic atoms. The need for more measurements and systematic calculations is discussed to allow the differentiation of different models of the Bohr-Weisskopf effect in nuclei.
Comments:
14 pages Updated due to an error in the magnetic moment of 193Ir (3/2) given in Table 2. The correct value is given now Update #2 due to error in magnetic moment of 200Hg, removal of BW data on 197Au as questions on the calculations have not been resolved
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex); Atomic Physics (physics.atom-ph)
arXiv:
2310.16398 [pdf]
3 citations
05
[Submitted on 25 Oct 2023]
Quadrupole-octupole coupling and the onset of octupole collectivity
K. Nomura
Octupole deformation and collective excitations are studied within the interacting boson model. By using the results of the self-consistent mean-field calculations with a universal energy density functional, the Hamiltonian of the interacting $s$ , $d$ , and $f$ boson system is completely determined. A global systematic study confirms that significant octupole effects are present in actinide, lanthanide, and rare-earth nuclei corresponding to particular nucleon numbers for which octupole correlations are empirically suggested to be enhanced.
Comments:
5 pages, 7 figures; Proceedings of the 17th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics (CGS17), Grenoble, 17-21 July 2023
Subjects:
Nuclear Theory (nucl-th); Nuclear Experiment (nucl-ex)
arXiv:
2310.16408 [pdf]
EPJ Web Conf.(2025)·0 citations
06
[Submitted on 25 Oct 2023]
Zero-sound modes for the nuclear equation of state at supra-normal densities
Jing Ye🇨🇳 · J. Margueron🇫🇷 · Niu Li🇨🇳 · W. Z. Jiang🇨🇳
The meaningful correlations between the zero-sound modes and the stiffness of the nuclear equation of state (EOS) are uncovered in nuclear matter with the relativistic mean-field theory. It is demonstrated that the high-density zero-sound modes merely exist in models with the stiff EOS. While the stiff EOS can be softened by including {\omega}-meson self-interactions (the {\omega}4 term), the weakened coupling of the {\omega}-meson self-interactions reignites the zero sound at high density. These results suggest that the high-density zero-sound modes can be used to probe the stiffness of the EOS at supra-normal densities. The implications and effects of zero sounds are also discussed in heavy ion collisions and neutron stars.
Subjects:
Nuclear Theory (nucl-th)
arXiv:
2310.16759 [pdf]
PRC(2023)·6 citations
07
[Submitted on 25 Oct 2023] (cross-list from hep-ph)
Dyson-Schwinger equations towards cold-dense QCD matter with improved truncations
Zhan Bai🇨🇳 · Yu-Xin Liu🇨🇳
We take the Dyson-Schwinger equation (DSE) approach of QCD to study the phase transition and the equation of state of cold dense matter. Besides the bare vertex and Gauss gluon model, we take into account an improved truncation scheme, the CLRQ vertex and infrared-constant gluon model. For the dynamical chiral symmetry breaking solution of the DSE, we require that the emergence of quark number density to be at the chemical potential for the nuclear liquid-gas phase transition to take place, by incorporating a chemical potential dependent modification factor to the gluon model. The result shows that our modified scheme can not only describe the phase transition of the cold dense matter well but also the deduced equation of state of the matter can describe the recent astronomical observations consistently.
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.16292 [pdf]
0 citations
08
[Submitted on 25 Oct 2023] (cross-list from hep-ph)
Diffusion model approach to simulating electron-proton scattering events
Peter Devlin🇺🇸 · Jian-Wei Qiu🇺🇸 · Felix Ringer🇺🇸 · Nobuo Sato🇺🇸
Generative AI is a fast-growing area of research offering various avenues for exploration in high-energy nuclear physics. In this work, we explore the use of generative models for simulating electron-proton collisions relevant to experiments like CEBAF and the future Electron-Ion Collider (EIC). These experiments play a critical role in advancing our understanding of nucleons and nuclei in terms of quark and gluon degrees of freedom. The use of generative models for simulating collider events faces several challenges such as the sparsity of the data, the presence of global or event-wide constraints, and steeply falling particle distributions. In this work, we focus on the implementation of diffusion models for the simulation of electron-proton scattering events at EIC energies. Our results demonstrate that diffusion models can accurately reproduce relevant observables such as momentum distributions and correlations of particles, momentum sum rules, and the leading electron kinematics, all of which are of particular interest in electron-proton collisions. Although the sampling process is relatively slow compared to other machine learning architectures, we find diffusion models can generate high-quality samples. We foresee various applications of our work including inference for nuclear structure, interpretable generative machine learning, and searches of physics beyond the Standard Model.
Comments:
14 pages, 10 figures, journal version
Subjects:
High Energy Physics — Phenomenology (hep-ph); High Energy Physics — Experiment (hep-ex); Nuclear Theory (nucl-th)
arXiv:
2310.16308 [pdf]
PRD(2024)·16 citations
09
[Submitted on 25 Oct 2023] (cross-list from hep-ph)
Constructing the Equation of State of QCD in a functional QCD based scheme
Yi Lu🇨🇳 · Fei Gao🇨🇳 · Bao-Chi Fu🇨🇳 · Hui-Chao Song🇨🇳 · Yu-Xin Liu🇨🇳
We construct the equation of state (EoS) of QCD based on the finite chemical potential information from the functional QCD approaches, with the assistance of the lattice QCD EoS. The obtained EoS is consistent with the up-to-date estimations of the QCD phase diagram, including a phase transition temperature at zero chemical potential of $T = 155$ MeV, the curvature of the transition line $κ = 0.016$ and also a critical end point at $(T, μ_{B}) = (118, 600)$ MeV. In specific, the phase diagram mapping is achieved by incorporating the order parameters into the EoS, namely the dynamical quark mass for the chiral phase transition together with the Polyakov loop parameter for the deconfinement phase transition. We also implement the EoS in hydrodynamic simulations to compute the particle yields, ratios and collective flow, and find that our obtained EoS agrees well with the commonly used one based on the combination of lattice QCD simulation and hadron resonance gas model.
Comments:
8 pages, 12 figures
Subjects:
High Energy Physics — Phenomenology (hep-ph); Nuclear Experiment (nucl-ex); Nuclear Theory (nucl-th)
arXiv:
2310.16345 [pdf]
PRD(2024)·16 citations
10
[Submitted on 25 Oct 2023] (cross-list from hep-th)
Baryons as Vortexes on the $η^{'}$ Domain Wall
Fan Lin🇨🇳 · Yong-Liang Ma🇨🇳
We show that the recent construction of $N_{f} = 1$ baryons on the $η^{'}$ domain wall can be understood as vortexes of the principal effective theory -- the Chern-Simons-Higgs theory -- on a 2+1-dimensional sheet. This theory has a series of vertex solutions, and the vortex with unit topological charge naturally spins $N_{c} /2$ , which coincides with the spin of the one-flavor baryon in QCD. Since the $N_{c}$ scaling of the vortexes is the same as that of baryons, baryons can be regarded as vortexes. By virtue of the particle-vortex symmetry, the dual Zhang-Hansson-Kivelson theory indicates that the quark carries topological charge $1/ N_{c}$ and obeys fractional statistics. The generalization to arbitrary $N_{f}$ is also discussed.
Comments:
13 pages
Subjects:
High Energy Physics — Theory (hep-th); High Energy Physics — Phenomenology (hep-ph); Nuclear Theory (nucl-th)
arXiv:
2310.16438 [pdf]
JHEP(2024)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE